combinatorics/enumeration.cpp

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• Last update: 2021-03-25 09:21:12+09:00

Required by

• combinatorics/bell.cpp
• combinatorics/bernoulli.cpp
• combinatorics/partition.cpp
• combinatorics/stirling1st.cpp
• combinatorics/stirling2nd.cpp
• combinatorics/surjection.cpp
• formalpowerseries/998244353.cpp
• formalpowerseries/base.cpp
• formalpowerseries/diff.cpp
• formalpowerseries/div.cpp
• formalpowerseries/exp.cpp
• formalpowerseries/integral.cpp
• formalpowerseries/inv.cpp
• formalpowerseries/log.cpp
• formalpowerseries/mod.cpp
• formalpowerseries/pow.cpp
• formalpowerseries/shift.cpp
• formalpowerseries/sqrt.cpp
• graph/lowlink.cpp
• includes/formalpowerseries.h
• polynomial/interpolate.cpp
• polynomial/multieval.cpp

Verified with

• test/aoj/2985.garner.test.cpp
• test/aoj/2985.test.cpp
• test/aoj/3072.test.cpp
• test/aoj/3084.test.cpp
• test/aoj/DPL_5_A.test.cpp
• test/aoj/DPL_5_B.test.cpp
• test/aoj/DPL_5_C.test.cpp
• test/aoj/DPL_5_D.test.cpp
• test/aoj/DPL_5_F.test.cpp
• test/aoj/DPL_5_G.test.cpp
• test/aoj/DPL_5_H.test.cpp
• test/aoj/DPL_5_I.test.cpp
• test/aoj/DPL_5_J.test.cpp
• test/aoj/DPL_5_K.test.cpp
• test/yosupo/bernoulli_number.test.cpp
• test/yosupo/exp_of_formal_power_series.test.cpp
• test/yosupo/inv_of_formal_power_series.test.cpp
• test/yosupo/log_of_formal_power_series.test.cpp
• test/yosupo/multipoint_evaluation.test.cpp
• test/yosupo/partition_function.test.cpp
• test/yosupo/polynomial_interpolation.test.cpp
• test/yosupo/polynomial_taylor_shift.test.cpp
• test/yosupo/pow_of_formal_power_series.test.cpp
• test/yosupo/sharp_p_subset_sum.test.cpp
• test/yosupo/sqrt_of_formal_power_series.test.cpp
• test/yosupo/stirling_number_of_the_first_kind.test.cpp
• test/yosupo/stirling_number_of_the_second_kind.test.cpp
• test/yukicoder/2744.test.cpp
• test/yukicoder/2772.test.cpp
• test/yukicoder/5633.test.cpp

Code

#ifndef call_from_test
#include <bits/stdc++.h>
using namespace std;
#endif

//BEGIN CUT HERE
template<typename M_>
class Enumeration{
  using M = M_;
protected:
  inline static vector<M> fact,finv,invs;
public:
  static void init(int n){
    n=min<decltype(M::mod)>(n,M::mod-1);

    int m=fact.size();
    if(n<m) return;

    fact.resize(n+1,1);
    finv.resize(n+1,1);
    invs.resize(n+1,1);

    if(m==0) m=1;
    for(int i=m;i<=n;i++) fact[i]=fact[i-1]*M(i);
    finv[n]=M(1)/fact[n];
    for(int i=n;i>=m;i--) finv[i-1]=finv[i]*M(i);
    for(int i=m;i<=n;i++) invs[i]=finv[i]*fact[i-1];
  }

  static M Fact(int n){
    init(n);
    return fact[n];
  }
  static M Finv(int n){
    init(n);
    return finv[n];
  }
  static M Invs(int n){
    init(n);
    return invs[n];
  }

  static M C(int n,int k){
    if(n<k or k<0) return M(0);
    init(n);
    return fact[n]*finv[n-k]*finv[k];
  }

  static M P(int n,int k){
    if(n<k or k<0) return M(0);
    init(n);
    return fact[n]*finv[n-k];
  }

  // put n identical balls into k distinct boxes
  static M H(int n,int k){
    if(n<0 or k<0) return M(0);
    if(!n and !k) return M(1);
    init(n+k);
    return C(n+k-1,n);
  }
};
//END CUT HERE
#ifndef call_from_test
//INSERT ABOVE HERE
signed main(){
  return 0;
}
#endif

#line 1 "combinatorics/enumeration.cpp"

#include <bits/stdc++.h>
using namespace std;
#endif

//BEGIN CUT HERE
template<typename M_>
class Enumeration{
  using M = M_;
protected:
  inline static vector<M> fact,finv,invs;
public:
  static void init(int n){
    n=min<decltype(M::mod)>(n,M::mod-1);

    int m=fact.size();
    if(n<m) return;

    fact.resize(n+1,1);
    finv.resize(n+1,1);
    invs.resize(n+1,1);

    if(m==0) m=1;
    for(int i=m;i<=n;i++) fact[i]=fact[i-1]*M(i);
    finv[n]=M(1)/fact[n];
    for(int i=n;i>=m;i--) finv[i-1]=finv[i]*M(i);
    for(int i=m;i<=n;i++) invs[i]=finv[i]*fact[i-1];
  }

  static M Fact(int n){
    init(n);
    return fact[n];
  }
  static M Finv(int n){
    init(n);
    return finv[n];
  }
  static M Invs(int n){
    init(n);
    return invs[n];
  }

  static M C(int n,int k){
    if(n<k or k<0) return M(0);
    init(n);
    return fact[n]*finv[n-k]*finv[k];
  }

  static M P(int n,int k){
    if(n<k or k<0) return M(0);
    init(n);
    return fact[n]*finv[n-k];
  }

  // put n identical balls into k distinct boxes
  static M H(int n,int k){
    if(n<0 or k<0) return M(0);
    if(!n and !k) return M(1);
    init(n+k);
    return C(n+k-1,n);
  }
};
//END CUT HERE
#ifndef call_from_test
//INSERT ABOVE HERE
signed main(){
  return 0;
}
#endif

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